Helicopter crash during search operation
Conveyed via the duty officer on Gullfaks C, the job involved looking for missing people who might be floating in the sea or injured on the rocks in the search area. The helicopter crashed while on its way.
It had made an intermediate landing on Gullfaks C to obtain information, and took off from there at about 19.00. Its flight to the search area was routine. The weather was not particularly good – overcast, with fairly heavy rain clouds along the coast, and a gale blowing. Visibility was about four kilometres. The pilots had little benefit of their radar for navigation, since it was difficult to distinguish echoes from the rain clouds and the terrain.
At 19.33.38, the helicopter hit the mountain on the west side of Alden island at a height of about 1 000 feet. The last radio contact was at 19.33.27, when the pilots reported that they saw “a fairly long island here”. Alden consists largely of the steep-sided Norskehesten mountain, with a highest point of 481 metres or 1 576 feet. No lighthouse or beacons are installed there.
The helicopter crew comprised a captain and chief officer, a technician/lift operator and a rescue officer working for Helikopter Service A/S, and an SAR nurse from Statfjord B employed by Statoil. All were killed instantly.
Several factors contributed to the accident. Under the pressure of saving life, not enough attention had been paid to rules and procedures for safe flying when making a landfall at an unknown location. The assignment was not adequately planned, and the company had not ensured suitable aviation charts.
The pilots were using the GNS 500 A navigation system, which was activated with Gullfaks C as the starting point, while the automated system used Statfjord B as its base.
When communicating with the air traffic controllers, the crew also mixed up metres and feet and mentally visualised a maximum height of 480 metres near the search area as 480 feet. They accordingly took 1 000 feet to be a safe height.
A side wind which strengthened after landfall was made also drove the helicopter to the left of its planned course, and the machine was further along this track than the navigation system indicated.
The crew probably based their navigation on visual identification of lights and terrain formations. Immediately before the accident, they were all fully occupied observing the ground beneath them. The darkness and thick cloud prevented them from spotting the Alden mountainside visually. When they also got the height of Norskehesten wrong, and thought 1 000 feet was safe, the accident could not be avoided.
Source
Accident Investigation Board Norway. Rapport om luftfartsulykke ved Alden i Askvoll den 3. oktober 1990 med Bell 214ST LN-OML. Published January 1992.